Embodiments of the present disclosure relate to sensor arrays, and more particularly to construction of modular sensor arrays.
Sensors or transducers are devices that transform input signals of one form into output signals of a different form. Commonly used transducers include light sensors, heat sensors, and acoustic sensors. An example of an acoustic sensor is an ultrasonic transducer. In ultrasound devices, the transducers transform signals of electrical energy into acoustic energy or produce electrical signals from absorbed sound waves.
Various applications, such as biomedical non-invasive diagnostics and non-destructive testing (NDT) of materials entail the use of sensor arrays, where the sensors are often configured in two-dimensions (that is, the X-Y plane). For example, ultrasonic transducer arrays are used in medical imaging, non-destructive evaluation (NDE) and other applications.
Applications such as medical and industrial imaging, non-destructive testing (NDT), security, baggage scanning, astrophysics and medicine may entail the use of sensors that encompass large areas. It may be noted that in the context of X-ray scanners and a single photon emission computed tomography (SPECT) imaging system, the large area sensor may include a sensor having an area of about 20 cm×20 cm for cardiac imaging and a sensor having an area of about 42 cm×42 cm for chest radiography. Also, for a computed tomography (CT) imaging system, the large area sensors may include sensors having an area of about 16 cm×90 cm. In the field of medical diagnostics, such as, but not limited to, X-ray, CT, ultrasound and mammography, it may be desirable to employ sensors that encompass large areas. For instance, in an X-ray imaging system, large area transducers may be necessary to encompass the area of the X-ray detector. Also, screening for internal bleeding and tumors entails use of much larger sensor arrays, typically on the order of 300 cm2. Moreover, in non-medical applications even larger arrays may be desired.
Currently available techniques typically form such large arrays by arranging a large number of transducer modules in rows and columns on one side of a connecting means, such as an interposer, and a corresponding number of integrated circuits on the other side of the connecting means. Unfortunately, this entails an increased wire density of the interposer to handle the circuit load, especially as the pitch on both the sensors and the integrated circuits decreases. Performance of such large area transducers is significantly degraded when there are significant variations in spacing between modules.
Moreover, various large area applications entail use of large area sensors of different sizes and shapes. The complexities and costs associated with building a single transducer to encompass a large area can be very significant. Furthermore, there are limitations of the manufacturing technologies with regard to the maximum size of the large area sensors that can be profitably manufactured. Additionally, the expenses incurred while repairing the large area sensors may be considerable.
It would therefore be desirable to develop a sensor module design that allows assembly of large area sensor arrays in order to circumvent associated problems, such as complexities and costs associated with manufacturing and repairing a single large area sensor. Furthermore, it would be desirable to tile the sensor modules efficiently to form a high-density large area sensor array in order to minimize system size, complexity, interconnect lengths and enhance the performance of the sensor arrays.